ReadOnlyCollection(Of T).Items Property

Returns the IList(Of T) that the ReadOnlyCollection(Of T) wraps.

Namespace:  System.Collections.ObjectModel
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Protected ReadOnly Property Items As IList(Of T)

Property Value

Type: System.Collections.Generic.IList(Of T)
The IList(Of T) that the ReadOnlyCollection(Of T) wraps.

Retrieving the value of this property is an O(1) operation.

Notes to Inheritors

This property is provided to allow direct access to members of the IList(Of T) that the ReadOnlyCollection(Of T) hides.

The following code example demonstrates several members of the ReadOnlyCollection(Of T) class. The code example creates a List(Of T) of strings and adds four dinosaur names to it. The code example then wraps the list in a ReadOnlyCollection(Of T).

After demonstrating the Count, Contains, Item, and IList.IndexOf members, the code example shows that the ReadOnlyCollection(Of T) is just a wrapper for the original List(Of T) by adding a new item to the List(Of T) and displaying the contents of the ReadOnlyCollection(Of T).

Finally, the code example creates an array larger than the collection and uses the CopyTo method to insert the elements of the collection into the middle of the array.


Imports System.Collections.Generic
Imports System.Collections.ObjectModel

Public Class Example

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      Dim dinosaurs As New List(Of String)

      dinosaurs.Add("Tyrannosaurus")
      dinosaurs.Add("Amargasaurus")
      dinosaurs.Add("Deinonychus")
      dinosaurs.Add("Compsognathus")

      Dim readOnlyDinosaurs As _
          New ReadOnlyCollection(Of String)(dinosaurs)

      outputBlock.Text &= vbCrLf
      For Each dinosaur As String In readOnlyDinosaurs
         outputBlock.Text &= dinosaur & vbCrLf
      Next

      outputBlock.Text &= String.Format(vbLf & "Count: {0}", _
          readOnlyDinosaurs.Count) & vbCrLf

      outputBlock.Text &= String.Format(vbLf & "Contains(""Deinonychus"" & vbCrLf: {0}", _
          readOnlyDinosaurs.Contains("Deinonychus"))

      outputBlock.Text &= String.Format(vbLf & _
          "readOnlyDinosaurs(3): {0}", readOnlyDinosaurs(3)) & vbCrLf

      outputBlock.Text &= String.Format(vbLf & "IndexOf(""Compsognathus"" & vbCrLf: {0}", _
          readOnlyDinosaurs.IndexOf("Compsognathus"))

      outputBlock.Text &= vbLf & "Insert into the wrapped List:" & vbCrLf
      outputBlock.Text &= String.Format("Insert(2, ""Oviraptor"")") & vbCrLf
      dinosaurs.Insert(2, "Oviraptor")

      outputBlock.Text &= vbCrLf
      For Each dinosaur As String In readOnlyDinosaurs
         outputBlock.Text &= dinosaur & vbCrLf
      Next

      Dim dinoArray(readOnlyDinosaurs.Count + 1) As String
      readOnlyDinosaurs.CopyTo(dinoArray, 1)

      outputBlock.Text &= String.Format(vbLf & "Copied array has {0} elements:", _
          dinoArray.Length) & vbCrLf
      For Each dinosaur As String In dinoArray
         outputBlock.Text &= String.Format("""{0}""", dinosaur) & vbCrLf
      Next

   End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Deinonychus
'Compsognathus
'
'Count: 4
'
'Contains("Deinonychus"): True
'
'readOnlyDinosaurs(3): Compsognathus
'
'IndexOf("Compsognathus"): 3
'
'Insert into the wrapped List:
'Insert(2, "Oviraptor")
'
'Tyrannosaurus
'Amargasaurus
'Oviraptor
'Deinonychus
'Compsognathus
'
'Copied array has 7 elements:
'""
'"Tyrannosaurus"
'"Amargasaurus"
'"Oviraptor"
'"Deinonychus"
'"Compsognathus"
'""


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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